Many of plastic bottles, metal cans, and the like containers have heat shrinkable labels thereon these days. Such heat shrinkable labels are produced by printing images on heat shrinkable films made of thermoplastic resin.
Heat shrinkable films are required to have various properties such as heat resistance, solvent resistance, and tearing properties along the perforation as well as low temperature shrinkability.
Such a heat shrinkable film contacts a metal control roll in subsequent processes such as printing or label processing, whereby the surface of the film is shaved off. The shavings of the film unfortunately foul the metal control roll.
In view of this, Patent Literature 1 discloses a method for improving antiwear properties of the film during film travelling by specifying the surface roughness of the film.